FORS_SPEC_MFLAT(7)

✨ fors_spec_mflat — the manual, but make it cute ✨

okay bestie, sit down, hydrate, because this is FORS_SPEC_MFLAT(7), a page straight outta the fors recipes collection, and it is lowkey doing the most important flat-fielding work in the whole pipeline. no cap. 💖

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🌸 NAME 🌸

fors_spec_mflat — computes the master spectroscopic flat, and it removes the bias first, because we do things in order around here 💅

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🦋 SYNOPSIS 🦋

esorex fors_spec_mflat [OPTIONS] FILE.sof

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🎀 DESCRIPTION 🎀

so this recipe's whole vibe is: take the master bias (the one that the fors_bias recipe already cooked up), and subtract it from a whole set of raw flat field frames. that's the job. main character energy only. ✨

here's the tea, step by step:

• the input raw frames get summed together
• the master bias frame gets rescaled to match
• then that rescaled bias gets subtracted from the summed result
• the overscan regions, if present, get used to compensate for variations of the bias level between the master bias and the input raw frames
• after all that, the overscan regions get trimmed from the result 🧚

also a tiny glossary moment: in the table below, the MXU acronym can alternatively be read as MOS and LSS. same energy, different letters. iykyk.

📥 Input files 📥

• DO category: SCREEN_FLAT_MXU — Type: Raw — Explanation: raw data frame — Required: Y ✅
• DO category: SLIT_LOCATION_MXU — Type: Calib — Explanation: slits positions on CCD — Required: Y ✅
• DO category: CURV_COEFF_MXU — Type: Calib — Explanation: slits tracing fits — Required: Y ✅
• DO category: DISP_COEFF_MXU — Type: Calib — Explanation: wavelength calibration — Required: Y ✅
• DO category: MASTER_BIAS — Type: Calib — Explanation: master bias frame — Required: Y ✅

(they're all required, bestie. every single one. bring the whole friend group or don't come at all 🫶)

📤 Output files 📤

• DO category: MASTER_SCREEN_FLAT_MXU — Data type: FITS image — Explanation: bias subtracted sum frame 🌈

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💅 OPTIONS 💅

seven options. iconic. let's get into it:

• --smooth_sed <float> — smoothing size for each flat sed. it's a float, and the default is 0.0. the full name of this option for the EsoRex configuration file is fors.fors_spec_mflat.smooth_sed [default = 0.0]. ✨
• --stack_method <str> — frames combination method. it's a str, and the default is ´sum´. the full name of this option for the EsoRex configuration file is fors.fors_spec_mflat.stack_method [default = sum]. 💖
• --klow <float> — low threshold in the ksigma method. float, default 3.0. the full name of this option for the EsoRex configuration file is fors.fors_spec_mflat.klow [default = 3.0]. 🦋
• --khigh <float> — high threshold in the ksigma method. float, default 3.0. the full name of this option for the EsoRex configuration file is fors.fors_spec_mflat.khigh [default = 3.0]. 🦋
• --kiter <int> — max number of iterations in the ksigma method. int, default 999. the full name of this option for the EsoRex configuration file is fors.fors_spec_mflat.kiter [default = 999]. 🔥
• --nonlinear_level <float> — the level above which the detector is not linear. float, default 50000.0. the full name of this option for the EsoRex configuration file is fors.fors_spec_mflat.nonlinear_level [default = 50000.0]. ⭐
• --max_nonlinear_ratio <float> — maximum allowed ratio of non-linear pixels per slit. float, default 0.2. the full name of this option for the EsoRex configuration file is fors.fors_spec_mflat.max_nonlinear_ratio [default = 0.2]. 👑

note that it's possible to create a configuration file containing these options, along with suitable default values. please refer to the details provided by the 'esorex --help' command. 📝

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👀 SEE ALSO 👀

the full documentation for the fors pipeline can be downloaded as a PDF file using the following URL:

ftp://ftp.eso.org/pub/dfs/pipelines/fors/fors-pipeline-manual-4.9.pdf

an overview over the existing ESO pipelines can be found on the web page https://www.eso.org/sci/software/pipelines/. 🌐

basic documentation about the EsoRex program can be found at the esorex (1) man page. 📖

it's possible to call the pipelines from python using the python-cpl package. see https://packages.python.org/python-cpl/index.html for further information. 🐍

the other recipes of the fors pipeline are — okay brace yourself, it's a long guest list:

fors_align_sky(7), fors_align_sky_lss(7), fors_bias(7), fors_calib(7), fors_config(7), fors_dark(7), fors_detect_objects(7), fors_detect_spectra(7), fors_extract(7), fors_extract_objects(7), fors_extract_slits(7), fors_flatfield(7), fors_img_science(7), fors_img_screen_flat(7), fors_img_sky_flat(7), fors_normalise_flat(7), fors_photometry(7), fors_pmos_calib(7), fors_pmos_extract(7), fors_pmos_science(7), fors_remove_bias(7), fors_resample(7), fors_science(7), fors_subtract_sky(7), fors_subtract_sky_lss(7), fors_sumflux(7), fors_trace_flat(7), fors_wave_calib(7), fors_wave_calib_lss(7), fors_zeropoint(7)

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⭐ VERSION ⭐

fors_spec_mflat 5.5.7

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🫶 AUTHOR 🫶

Carlo Izzo <usd-help@eso.org>

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😭 BUG REPORTS 😭

please report any problems to usd-help@eso.org. alternatively, you may send a report to the ESO User Support Department <usd-help@eso.org>. they're literally the same address but go off, tell them twice, they love that 💜

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📜 LICENSE 📜

this file is currently part of the FORS Instrument Pipeline Copyright (C) 2002-2011 European Southern Observatory.

this program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

this program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

you should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

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okay that's the whole page, no skips, no skimming, every last flag accounted for 💖 version 5.5.7 of fors_spec_mflat, page FORS_SPEC_MFLAT(7), straight from the fors recipes. go forth and flatten those spectra, bestie, you've got this 🌸✨🎀